<!DOCTYPE html>
<div role="tree" id="tree">
  <div role="group" aria-hidden="true">
    <div role="treeitem" tabindex="0">
      outer aria-hidden
    </div>
    <div role="treeitem" tabindex="0">
      <div>
        <div>outer aria-hidden, grandchildren</div>
      </div>
    </div>
  </div>
  <div role="group">
    <div role="treeitem" tabindex="0" aria-hidden="true">
      direct aria-hidden
    </div>
    <div role="treeitem" tabindex="0" aria-hidden="true">
      <div>
        <div>direct aria-hidden, grandchildren</div>
      </div>
    </div>
    <div role="treeitem" tabindex="0">
      <div aria-hidden="true">
        <div>inner aria-hidden, grandchildren</div>
      </div>
    </div>
  </div>
</div>
